Hong Kong's South China Morning Post cited Beijing News and Beijing Times as saying Chan and his friend were detained by Beijing police.
China Central Television also confirmed Ko's arrest in a report this afternoon following a rumour on the Internet last night and claims by Ko's manager that he was unable to contact the actor.
Apple Daily Taiwan cited an unnamed source as saying both Ko, 23, and Chan, 31, were nabbed in Beijing late last Tuesday night.
The Straits Times